Called a neutron star, the dense, crumbling remains of a massive star weigh more than twice the mass of our sun, making it the heaviest neutron star known to date. The object rotates 707 times per second, which also makes it one of the fastest spinning neutron stars in the Milky Way.
The neutron star is known as the black widow because it is very similar to these well-known spiders Female spiders eating much smaller male partners after mating, the star rips apart and devours almost the entire mass of its companion star.
This stellar feast allowed the Black Widow to become the heaviest neutron star observed to date.
Astronomers were able to weigh the star, called PSR J0952-0607, by Using the sensitive Keck telescope at the WM Keck Observatory in Maunakea, Hawaii.
The observatory’s Low Resolution Imaging Spectrometer recorded visible light from the torn companion star, which glowed because of its high temperature.
The companion star is now the size of a large gaseous planet, or 20 times the mass of Jupiter. The side of the companion star facing the neutron star is heating up to 10,700 degrees Fahrenheit (5927 degrees Celsius) — hot and bright enough to be seen by a telescope.
Neutron star cores are the densest matter in the universe, outside of black holes, and 1 cubic inch (16.4 cubic centimeters) of a neutron star weighs more than 10 billion tons, according to study author Roger W. Romani, a professor of physics at Stanford University in California.
This particular neutron star is the densest object within sight of Earth, according to the researchers.
“We know roughly how matter behaves at nuclear densities, as it does in the nucleus of a uranium atom,” study co-author Alex Filippenko said in a statement. Filippenko holds the double titles of Professor of Astronomy and Distinguished Professor physics At the University of California, Berkeley.
“A neutron star is like one giant core, but when you have one and a half solar masses of that matter, which is about 500,000 Earth masses of cores all clinging to each other, it’s not at all clear how they’re going to behave.”
A neutron star like PSR J0952-0607 is called a pulsar because as it rotates, the object acts like a cosmic beacon, regularly emitting light via radio waves, X-rays, or gamma rays.
Ordinary pulsars rotate and flash about once per second, but this star pulsates hundreds of times per second. This is because the neutron star becomes more active as it sweeps material away from the companion star.
“In the case of cosmic ingratitude, the Black Widow pulsar, which devoured a large part of its companion, is now heating up and evaporating into planetary masses and possibly complete annihilation,” Filippenko said.
Astronomers discovered for the first time The neutron star in 2017, and Filippenko and Romani have studied similar black widow systems for more than a decade. They were trying to understand how big neutron stars can get. If neutron stars get too heavy, they collapse and become black holes.
The researchers said the star PSR J0952-0607 is 2.35 times the mass of the Sun, which is now considered the upper limit of a neutron star.
“We can continue to look for black widows and similar neutron stars skating close to the edge of the black hole. But if we don’t find any, it hardens the argument that 2.3 solar masses is the true limit, after which they become black holes,” Filipenko said.